Why don't I have the home screen on my Lumia 930?

I have installer WP10 Preview. After the installation, I did hard reset from Settings menu. After hard reset, I was asked few questions (home country, language ..., connect to WiFi and Cellular), but when I was prompted to sign in to MS account, I got the message it is not available at the moment. After this, I have only Apps list (very few apps), no home screen and nothing I can do.